In 2008, U.S. firms spent $24.2 billion on R&D in Europe, about 64% of the $37 billion worldwide total, compared with $7.21 billion in Asia. Europe's been the largest recipient at least since 1998, when U.S. companies spent $10.4 billion, compared to $1.6 billion in Asia.

Here's a map showing expenditures in and out of the U.S. for all other regions. Notice Canadian firms have actually reduced spending here over the past decade, while Africa and South America have ramped up American R&D (though we haven't exactly reciprocated).

National Science Foundation

Spending on chemicals development, which includes pharmaceuticals, took the greatest share of U.S. multinational spending in Europe, at $6.25 billion. Likewise, among European firms performing R&D in the U.S., chemicals spending accounted for a majority, with Switzerland spending $5.4 billion here.